Complement C2 polymorphisms in children with Henoch Schönlein purpura

Abstract

Purpose: The aim of this study was to investigate whether C2 polymorphisms influence the symptoms and disease outcomes in children with Henoch Schönlein purpura (HSP).Materials and Methods: This cross-sectional study included 49 children with HSP, diagnosed and followed for at least 6 months in our department between July 2016 and March 2018. Sanger sequencing was performed for detecting C2 gene polymorphisms. Statistical analysis was performed for comparison of clinical and laboratory parameters between patients according to having C2 polymorphisms.Results: Only 6 patients (12.2%) had following C2 gene polymorphisms: rs9332739 (n=3), rs36221133 (n=2), rs146054348 (n=1). Age at disease onset, gastrointestinal and joint involvement, serum complement levels, renal involvement, requirement of systemic steroids and disease relapse were found similar between the patients with and without C2 gene polymorphism. We found higher serum IgM level and lower leukocyte counts in HSP patients with confirmed C2 polymorphisms than the patients with normal C2 gene.Conclusion: Although C2 gene polymorphisms were not related to clinical manifestations and disease outcome in children with HSP, we speculate that C2 gene polymorphisms may be associated with elevated serum IgM levels in patients with HSP.